Movement products likely to be cause of ASF spread in China - FAO

Movement of products, rather than pigs, is likely to be responsible for the spread of African swine fever in China, according to the United Nations Food and Agriculture Organization (FAO). 

China is currently bracing itself for further African swine fever (ASF) outbreaks, while there are also fears the virus could spread to neighbouring countries.

So far, the Chinese authorities have culled more than 24,000 pigs in four provinces, following confirmation of four cases so far in August. China accounts for approximately half the global pig population, estimated at 500 million.

The country’s agriculture ministry has said it cannot rule out the possibility of new outbreaks, as the risk of ASF transmission from neighboring countries remains large, it said, according to an Asian news channel. The ministry acknowledged that it is not clear how widely the disease has spread, and that there is much uncertainty over how the situation will develop.

The FAO has warned that the rapid onset of ASF in China and its detection in areas more than 1,000 kilometres apart could mean ‘the deadly pig virus may spread to other Asian countries anytime’. It fears that the disease will cross to neighbouring countries of Southeast Asia or the Korean Peninsula where trade and consumption of pork products is also high.

The ASF virus is very hardy and can survive long periods in very cold and very hot weather, and even in dried or cured pork products. The strain detected in China is similar to one that infected pigs in eastern Russia in 2017 but, so far, and while the investigations continue, the China Animal Health and Epidemiology Center has found no conclusive evidence of this latest outbreak's source or linkages.

"The movement of pig products can spread diseases quickly and, as in this case of ASF, it's likely that the movement of such products, rather than live pigs, has caused the spread of the virus to other parts of China," said Juan Lubroth, FAO's Chief Veterinarian.

There is no effective vaccine to protect swine from the disease. And, while the disease poses no direct threat to human health, outbreaks can be devastating with the most virulent forms lethal in 100 per cent of infected animals, the FAO added.

Emergency measures

In a statement on its website, the Chinese agriculture ministry pointed out that ASF is not a zoonotic disease. It warned pig producers to ‘stop pig transportation from infected areas, pay attention to daily disinfection, keep pigs in closed zones and take isolative protection measures’.

“Meanwhile, pigs should be kept away from wild boars and ornithodoros papillipes (ticks) and pig farmers are prohibited from feeding pig with swill and food wastes without high-temperature treatment,” the statement added, urging farmers to report unexplained death with ASF symptoms ‘in a timely manner’.

The ministry said emergency measures taken in response to the first outbreak, detected in Shenyang, in the Liaoning Province on August 3, ensure that ‘at present, the epidemic has been effectively controlled’. A total of 47 pigs out of 383 on the farm died.

However, the virus has also been detected in other parts of the country, with infected pigs known to have travelled long distances to abattoirs. China announced its fourth case last week in the province of Zhejiang, four days after it was reported in neighboring Jiangsu, which is more than 1,000 kilometres from the initial outbreak.